Absorption spectroscopy is heavily used to monitor trace gases. The Herriott cell is an optical device which has proven to be a useful multipass cell design for trace gas measurement. Herriott cells typically employ two mirrors with equal radii of curvature that propagate a light beam within the cavity. It is readily constructed, is well understood, and is relatively insensitive to mirror misalignment. In such devices, multiple passes are made by the probe light in the optical cavity. In addition, the long linear optical cavity also contributes to a long path length. The Herriott cell is also suited to laser-based systems due to its ability to re-image, or refocus, a light beam as the beam traverses the optical cavity, which keeps the beam restricted within the cavity boundaries and conserves power density of the beam as it propagates within the cavity. However, the long linear cavity of a Herriott cell can provide opportunity for tenacious gas species to attach to sites along the cell wall, making purging of the cavity between measurements difficult, leading to increased measurement cycle times, especially in reduced pressure systems. Further, multi-wavelength cell designs require numerous penetrations in the end mirror with attendant mechanical interferences between the different launch and detection optics. Accordingly, new designs for gas absorption devices are needed that: 1) provide optimum path length for absorption of light in a preselected gas, 2) are easily aligned and not prone to optical misalignment, 3) minimize wall effects, and 4) provide an optical cavity capable of measuring various chemical species of interest using different wavelengths of light.